--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2006-10-18  Bruno Haible  <bruno@clisp.org>
+
+	* lib/lock.h [C++]: Wrap definitions in extern "C".
+
 2006-10-18  Bruno Haible  <bruno@clisp.org>
 
 	* gnulib-tool (func_emit_initmacro_end): Remove duplicates from the

--- a/lib/lock.h
+++ b/lib/lock.h
@@ -1,5 +1,5 @@
 /* Locking in multithreaded situations.
-   Copyright (C) 2005 Free Software Foundation, Inc.
+   Copyright (C) 2005-2006 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -70,6 +70,10 @@
 # include <pthread.h>
 # include <stdlib.h>
 
+# ifdef __cplusplus
+extern "C" {
+# endif
+
 # if PTHREAD_IN_USE_DETECTION_HARD
 
 /* The pthread_in_use() detection needs to be done at runtime.  */
@@ -355,6 +359,10 @@
     while (0)
 extern int glthread_once_singlethreaded (pthread_once_t *once_control);
 
+# ifdef __cplusplus
+}
+# endif
+
 #endif
 
 /* ========================================================================= */
@@ -366,6 +374,10 @@
 # include <pth.h>
 # include <stdlib.h>
 
+# ifdef __cplusplus
+extern "C" {
+# endif
+
 # if USE_PTH_THREADS_WEAK
 
 /* Use weak references to the GNU Pth threads library.  */
@@ -468,6 +480,10 @@
 extern void glthread_once_call (void *arg);
 extern int glthread_once_singlethreaded (pth_once_t *once_control);
 
+# ifdef __cplusplus
+}
+# endif
+
 #endif
 
 /* ========================================================================= */
@@ -480,6 +496,10 @@
 # include <synch.h>
 # include <stdlib.h>
 
+# ifdef __cplusplus
+extern "C" {
+# endif
+
 # if USE_SOLARIS_THREADS_WEAK
 
 /* Use weak references to the old Solaris threads library.  */
@@ -600,6 +620,10 @@
 extern void glthread_once (gl_once_t *once_control, void (*initfunction) (void));
 extern int glthread_once_singlethreaded (gl_once_t *once_control);
 
+# ifdef __cplusplus
+}
+# endif
+
 #endif
 
 /* ========================================================================= */
@@ -608,6 +632,10 @@
 
 # include <windows.h>
 
+# ifdef __cplusplus
+extern "C" {
+# endif
+
 /* We can use CRITICAL_SECTION directly, rather than the Win32 Event, Mutex,
    Semaphore types, because
      - we need only to synchronize inside a single process (address space),
@@ -741,6 +769,10 @@
     glthread_once (&NAME, INITFUNCTION)
 extern void glthread_once (gl_once_t *once_control, void (*initfunction) (void));
 
+# ifdef __cplusplus
+}
+# endif
+
 #endif
 
 /* ========================================================================= */